Darbepoetin Alfa: A Novel Erythropoiesis-Stimulating Protein

OBJECTIVE: To review the pharmacology, pharmacokinetics, clinical efficacy, and safety of darbepoetin alfa. DATA SOURCES: Pertinent references were identified by a MEDLINE search (1995–January 2001) of the medical literature, review of English-language literature and references of these articles, product information, and abstracts from professional meetings. STUDY SELECTION: Clinical efficacy data were gathered from all available trial data citing darbepoetin alfa. Additional information concerning pharmacology, pharmacokinetics, and safety was also reviewed. DATA SYNTHESIS: Darbepoetin alfa is a new erythropoiesis-stimulating protein with a threefold longer half-life than recombinant human erythropoietin (r-HuEPO). Darbepoetin alfa is approved for intravenous and subcutaneous administration in patients requiring and not requiring dialysis. Clinical studies in patients with chronic kidney disease (CKD) have shown darbepoetin alfa to be equivalent to r-HuEPO in terms of increases in hemoglobin concentration, percentage of patients obtaining target hemoglobin, and average time to reach target hemoglobin concentration. Trials are currently ongoing in patients receiving cancer chemotherapy. The adverse event profile appears to be similar between the 2 agents. CONCLUSIONS: The equivalent efficacy and safety profile, as well as the longer half-life, may make darbepoetin alfa an attractive alternative to r-HuEPO in patients with CKD. Since these patients need to receive r-HuEPO 1–3 × weekly at the expense of increased healthcare utilization to improve their hemoglobin, agents such as darbepoetin alfa, with longer durations of action, may reduce healthcare expenses. In addition, enhanced patient compliance may be realized with once-weekly or once every-other-week administration.